1. Technical Field
The present disclosure relates to a method for erasing data recorded in a redundant arrays of inexpensive disks (RAID) system in which a plurality of write-once optical discs are used.
2. Description of Related Art
A write-once optical disc such as a DVD-R and a BD-R is a recording medium in which a recording mark recorded once cannot be rewritten. Unexamined Japanese Patent Publication No. 2002-245635 discloses an optical disc data erasing device that erases data recorded in the write-once optical disc.
The optical disc data erasing device of Unexamined Japanese Patent Publication. No. 2002-245635 overwrites the recorded data by irradiating the recorded data with a laser beam having recording power during the recording, which allows the recorded data to be erased. Therefore, the erased point becomes unreadable.
On the other hand, because the optical disc is an exchangeable recording medium, a defect can exist on a recording surface due to dust or a flaw. For this reason, in an optical disc drive that performs recording and reproduction on the optical disc, generally, defect management is performed in order to ensure reliability of the recorded or reproduced data (for example, see Unexamined Japanese Patent Publication No. 2011-154777).
Additionally, the RAID system can be configured by using a plurality of optical discs in order to improve the reliability. In a recording device of International Patent Publication No. 2013/005418, a plurality of recording mediums are accommodated in a magazine, the recording medium in the magazine is carried to a plurality of drive units in the recording device, and a RAID controller that performs parallel recording on the plurality of recording mediums is provided. This allows the RAID system to be configured on a magazine-by-magazine basis.